1. Field of the Invention
The present invention relates to an electrical connector and a terminal thereof, and more particularly to a land grid array electrical connector and a terminal thereof for electrically connecting a chip module to a circuit board.
2. Description of the Related Art
China patent 200720056219.9 discloses an electrical connector connecting to a circuit board. The electrical connector includes a plurality of terminals. The terminal has a base, and one side of the base extends to form a flexible arm. The flexible arm includes a contact arm that extends upward and a retaining portion that extends downward. The upper end of the base has one upward extension forming a carrier strip connecting portion and one downward extension forming a connecting portion which further extends downward to form a welding portion.
The base is located in a receiving slot of an insulating housing. The contact arm of the terminal exposes to the outside of the insulating housing. One side of the welding portion of the terminal has a hook for being wedged in a convex portion of the receiving slot to prevent the terminal from moving upward. The retaining portion of the terminal is received in a concave receiving portion of the insulating housing.
The terminal discussed above has the following characteristics. When the contact arm is pressed by an electronic component, at least one part of the retaining portion will contact the interior of the receiving concave portion. The retaining portion can absorb the external force and reduce the stress transmitted to the welding portion, thus minimize the risk of solder-crack. However, the conventional terminal still has the following drawbacks.
On a conventional terminal, such as disclosed in the referenced patent, when a solder ball is inserted and presses against the welding portion, the welding portion elastically moves away from the solder ball. When the solder ball reaches the prearranged position, an elastic restoring force exerted on the solder ball by the welding portion is limited as the welding portion extend vertically downwards, which leads to a small elastic restoring force and slow elastic restoration, so that the welding portion cannot be in close interference with the solder ball, the solder ball may fall off, resulting in poor connection between the terminal and the circuit board.